The first attempts to produce an implantable artificial organ in humans or animals took place a number of decades ago. The objective is to replace a missing organ with a device containing cells satisfying at least one function of said organ while avoiding the constraints of a transplant.
Document FR 2 384 504 already proposes an artificial pancreas supplied with a body fluid to be treated. The fluid passes through a serpentine element housed in a chamber that contains pancreatic islets. The wall of the serpentine element is made of a material that enables exchanges of molecules of low molecular weight such as insulin and glucose, but that forms a barrier to larger molecules such as antibodies and antigens. However, such a device is not implantable.
An implantable artificial organ was proposed by document WO 94/18906. Cells are contained in an envelope made of a semi-permeable membrane, which envelope is contained in another container providing mechanical protection of the first envelope. The cells are, for example, thyroid cells, parathyroid gland cells, adrenal gland cells, liver cells or pancreas cells. The replacement of the cells requires complete replacement of the device.
Document EP 664 729 proposes an implantable and refillable artificial pancreas.
Semi-permeable membranes have been the subject of numerous much research projects. Document WO 02/060409 proposes, for example, a semi-permeable membrane for encapsulating cells made of porous polycarbonate and surface-treated with a hydrophilic polymer. These membranes have the expected characteristics, namely good control of permeability, allowing the nutrients and substances generated by the cells of the artificial organ to quickly pass, limited adhesion of the cells on the surface of the membrane so as not to hinder the exchanges, good mechanical resistance and impermeability to large molecules. However, pouches made of this material do not control the distribution of the islets inside. Masses may form, which then have trouble exchanging nutrients and substances produced.
Accordingly, there is a need for a pouch for forming an implantable artificial organ that ensures good distribution of active cells and that is resistant during and after implantation of the pouch.